Working Party on Decommissioning and Dismantling (WPDD)

Overview

Within the NEA, the Working Party on Decommissioning and Dismantling (WPDD) of the RWMC provides a focus for the analysis of decommissioning policy, strategy and regulation, including the related issues of management of materials, release of buildings and sites from regulatory control and associated cost estimation and funding. Beyond policy and strategy considerations, the WPDD also reviews practical considerations for implementation such as techniques for characterisation of materials, for decontamination and for dismantling.

The WPDD brings together senior experts in decommissioning from 21 OECD and observer countries: Belgium, Canada, Czech Republic, Finland, France, Germany, Hungary, Italy, Japan, Korea, Netherlands, Norway, Poland, Romania, Russia, Slovak Republic, Spain, Sweden, United Kingdom and the United States, with involvement also from other international organisations such as the European Commission and the International Atomic Energy Agency (IAEA). Its membership includes policy specialists, regulators, implementers, researchers and waste management experts. It has a specialist sub-group devoted to the exchange of information and experience on costing issues, the Decommissioning Cost Estimation Group (DCEG).

WPDD tracks decommissioning developments worldwide and develops reports and position papers on emerging issues. Its overarching aim is to contribute to the development of best practice through circulation of its reports and through dialogue between policy makers, practitioners, regulators, researchers and international organisations.

Annual meetings and workshops

The WPDD meets once each year, at a host location that rotates among the member countries. Each meeting normally includes a topical session on an issue of special interest, and a session focussing on the framework for decommissioning in the host country. After the meeting, the host country normally arranges a visit to a local facility undergoing decommissioning.

In meetings, workshops and joint projects, the WPDD collaborates with other groups working in the field of decommissioning. These include the NEA’s programme for the exchange of scientific and technical information on the decommissioning of nuclear installations (CPD), as well as the NEA Forum on Stakeholder Confidence (FSC), to help reflect on the links between decommissioning, decision-making and public confidence, and with the RWMC Regulators’ Forum on regulatory issues.

Symposium on the Recycling of Metals Arising from Operation and Decommissioning of Nuclear Facilities

The Symposium on the Recycling of Metals Arising from Operation and Decommissioning of Nuclear Facilities was held on 8-10 April 2014 at Studsvik’s facility in Nyköping, Sweden. The Symposium, hosted by Studsvik AB in conjunction with the NEA and the IAEA, covered a wide range of topics concerning current practice, experiences and innovations within the management of contaminated metallic radioactive material. Presentations split into six topical sessions and a poster session were viewed by over 160 participants from 19 countries, the International Atomic Energy Agency, the World Nuclear Association, and the OECD. Download the symposium documents here.

Workshop on Radiological Characterisation for Decommissioning

In co-operation with Studsvik Nuclear AB, the Swedish Radiation Safety Authority (SSM), the Swedish Nuclear Fuel and Waste Management AB (SKB) and AB SVAFO, the NEA held a workshop on Radiological Characterisation for Decommissioning on 17-19 April 2012 in Studsvik, Sweden. Over 120 participants attended from 23 countries, the International Atomic Energy Agency (IAEA), the World Nuclear Association, the European Commission (EC) and the OECD. Participants shared current practices, lessons learnt and innovation in radiological characterisation for decommissioning of nuclear sites and facilities. Download the workshop documents here.

Special Seminar Commemorating the 10th Anniversary of the WPDD

The WPDD celebrated its 10th anniversary with a one-day seminar during its 15-17 November 2011 meeting. Approximately 40 decommissioning experts attended the seminar to discuss the current status of decommissioning; challenges to decommissioning including financial, infrastructure and human resources issues; lessons learnt from the Fukushima Daiichi nuclear accident; and decommissioning in the next decade. Future endeavours of the WPDD were also discussed in the context of the anniversary seminar. Download all the seminar presentations here.

The Decommissioning and Dismantling of Nuclear Facilities in NEA Member Countries: National Fact Sheets

These country reports and profiles present the radioactive waste management and decommissioning programmes of OECD/NEA member countries. They include information on national policies and strategies for decommissioning as well as on current decommissioning projects and associated funding arrangements and research programmes.

Task Groups of the WPDD

Task Group for Preparing for Decommissioning During Operation and Final Shutdown (TGPFD)

Decommissioning Cost Estimation Group (DCEG)

The WPDD Decommissioning Cost Estimation Group (DCEG) was created to foster the exchange of information and experience on issues in this field. In promoting collective learning on the subject, it aims to enhance the credibility, reliability, and auditability of the cost estimation process - thereby enhancing stakeholder confidence in the process of managing radioactive waste management liabilities. The group helps define best practices in the field of decommissioning cost estimation and to examine the scope for achieving consensus on overall objectives and developing common approaches.Members only area (requires password | reminder)

Task Group on Radiological Characterisation and Decommissioning (TG-RCD)

The aim of the task group is to identify and present the best practice for radiological characterisation at different stages of decommissioning and to point to areas that could or should be developed further by international cooperation and coordination. The main objective is to develop a status report on selection and tailoring of strategies for radiological characterisation and their importance for safe decommissioning of nuclear facilities.Members only area (requires password | reminder)

Task Group on Nuclear Site Restoration (TGNSR)

The task group aims to share strategic knowledge of international experience, approaches and constraints on the restoration of nuclear sites, management of land and groundwater that are affected by radiological, chemical and/or hazardous materials contamination. The report to be produced will contain observations and recommendations to consider in the development of strategies and plans for site restoration at nuclear sites to support on-going and new projects to achieve improvements in land quality management consistent with best practice. Members only area (requires password | reminder)

WPDD studies and reports

Radiological Characterisation for Decommissioning of Nuclear Installations (2013)
Radiological characterisation is critical to inform decision making and investments during all phases of the life cycle of a nuclear installation. There are different considerations for design, construction, operation, transition, decommissioning – the major waste management challenge – and finally site release. Radiological characterisation to support the decommissioning process is required with different aims and intensity throughout the different phases, but in particular during the transition phase when operation has ceased, and during the implementation of decommissioning.

The report provides guidance on selection and tailoring strategies for radiological characterisation, and gives an overview of best practice for radiological characterisation at different phases of the life cycle of a nuclear installation.

Cost Control Guide for Decommissioning of Nuclear Installations (2013)The Cost Control Guide provides a practical, user friendly approach to implementing cost and schedule controls for decommissioning programs to minimize project budget and schedule overruns. The Guide establishes a framework for structuring a program for preparing cost controls, training and certifying, based on the internationally recognised standard, Earned Value Management System (ANSI, 2007).

The Earned Value Management System (EVMS) is built on a work breakdown structure of decommissioning activities, and a defined process for controlling a project. The EVMS not only provides measurement of project status and future performance, but also builds a structure and culture for accountability on project performance. The success of the EVMS programme depends on management commitment to implement a culture change for its employees, and to impose the EVMS on potential future contractors performing decommissioning work at a facility.

The Management of Large Components from Decommissioning to Storage and Disposal (2012)
Dismantled components may either be segmented in order to put the pieces in standardised containers or removed as single or multiple large pieces for treatment or transportation to a disposal facility. Both options have been used and experience exists in most countries with mature nuclear programmes. The considerations and criteria leading to such decisions are multifaceted and include both legal and regulatory aspects dealing notably with transportation, disposal and waste-acceptance criteria, as well as the availability and acceptance of sized transport containers and dose limits.

The study provides the basis for the different involved parties to reach convergence on the most relevant management option from an overall point of view, identifies which criteria should be assessed in order to appreciate that relevancy, and promotes a communication tool that benefits from the experience gained by the different countries dealing with that issue.

International Structure for Decommissioning Costing (ISDC) of Nuclear Installations (2012)
Cost estimation for the decommissioning of nuclear facilities can vary considerably in format, content and practice both within and across countries. These differences may have legitimate reasons but make the process of reviewing estimates complicated and the estimates themselves difficult to defend. Hence, the joint initiative of the OECD Nuclear Energy Agency (NEA), the International Atomic Energy Agency (IAEA) and the European Commission (EC) was undertaken to propose a standard itemisation of decommissioning costs either directly for the production of cost estimates or for mapping estimates onto a standard, common structure for purposes of comparison. This report updates the earlier itemisation published in 1999 and takes into account experience accumulated thus far. The revised cost itemisation structure has sought to ensure that all costs within the planned scope of a decommissioning project may be reflected. The report also provides general guidance on developing a decommissioning cost estimate, including detailed advice on using the structure.

Decommissioning Considerations for New Nuclear Power Plants (2010)Applying Decommissioning Experience to the Design and Operation of New Plants (2010)
Experience from decommissioning projects suggests that the decommissioning of nuclear power plants could be made easier if this aspect received greater consideration at the design stage and during operation of the plants. Better forward planning for decommissioning results in lower worker doses and reduced costs. When appropriate design measures are not taken at an early stage, their introduction later in the project becomes increasingly difficult. Hence, their early consideration may lead to smoother and more effective decommissioning operations. This report provides an overview of key decommissioning issues which are useful to consider when designing new nuclear power plants.

Cost Estimation for Decommissioning: An International Overview of Cost Elements, Estimation Practices and Reporting Requirements (2010)Towards Greater Harmonisation of Decommissioning Cost Estimates (2010)
It is now common practice for decommissioning plans and associated cost estimates to be prepared for all nuclear installations. Specific requirements are generally set out in regulations which have their basis in national legislation. These estimates are important for ensuring that the necessary funds are being collected to cover the actual costs of decommissioning the facility. Important considerations in ensuring accurate cost estimates include: methodological accuracy and consistency, avoiding changes in project scope, good characterisation, consistent regulatory requirements, the plant operator, the approach to setting contingency levels, and risk management. Current good practices also include the use of a standardised list of activities, a strong quality assurance programme, use of a dedicated decommissioning core group, and involvement of regulators and stakeholders in the planning of decommissioning.

Applying Decommissioning Experience to the Design and Operation of New Nuclear Power Plants (2009)
Although the decommissioning of a nuclear facility occurs many decades after its construction, important provisions for decommissioning need to be incorporated at the plant design stage. The third generation nuclear power plants incorporate many improvements that facilitate dismantling. These also provide for easier replacement of components, more efficient maintenance, greater safety and/or lower costs during plant operation. Key design considerations include incorporation of modular concepts, innovations in equipment, materials and system layout, and measures to reduce potential levels of contamination, e.g. by careful selection of materials to reduce activity buildup and by use of fewer components and less piping.

Regulators increasingly require that a decommissioning plan be provided at the time of the request of a construction or operating license and that this plan be updated regularly during plant operation. This requirement, coupled with the need for transparent financial guarantees or the timely accumulation of decommissioning funds, makes decommissioning an integral part of lifetime plant management.

Regulating the Decommissioning of Nuclear Facilities (2008)
After a nuclear facility is shut down for the final time, the next steps involve reducing the sources of hazard in a systematic and progressive way. This involves removal of as much of the nuclear material as possible. In addition, other hazards such as those associated with operations at high temperatures and pressures are also reduced. Against this, however, some short-term hazards may be introduced because of the need to dismantle certain safety systems and confinement barriers in order to remove the inventory of radioactive materials. The activities connected with the process of decommissioning are rather different from the day-to-day activities on an operating plant in steady state. Moreover, they vary and change progressively as the decommissioning process progresses. Frequent change of decommissioning personnel and increasing conventional safety culture are also new challenges. Regulatory requirements and practices need to be adapted to the continuously changing situation in order to maintain a flexible and proportionate balance between regulatory requirements and the changing nature of the residual risk.

Achieving the Goals of the Decommissioning Safety Case (2005)
The removal of fuel from a shutdown nuclear facility eliminates the major source of radiological hazard i.e. that associated with nuclear operation. This, together with the cessation of operations at high temperatures and pressures, means that risks to public health and to the environment are significantly reduced. The process of decommissioning does however include dismantling operations and waste treatment processes with associated conventional and radiological hazards. Some radiological hazards for the workforce remain because of the possibly of coming into contact with radioactively contaminated or activated material.

Regulators today adapt their procedures to the changing levels of risk in a nuclear facility that is undergoing decommissioning. One emerging practice involves greater use of internal authorisation systems for minor plant modifications, with a first level of oversight by an independent safety committee established by the plant operator. In this situation national regulatory resources are focussed on issues with greater safety or environmental significance.

Release of Radioactive Materials and Buildings from Regulatory Control (2008)After a nuclear facility is shut down for the final time, the next steps involve reducing the sources of hazard in a systematic and progressive way. This involves removal of as much of the nuclear material as possible. In addition, other hazards such as those associated with operations at high temperatures and pressures are also reduced. Against this, however, some short-term hazards may be introduced because of the need to dismantle certain safety systems and confinement barriers in order to remove the inventory of radioactive materials. The activities connected with the process of decommissioning are rather different from the day-to-day activities on an operating plant in steady state. Moreover, they vary and change progressively as the decommissioning process progresses. Frequent change of decommissioning personnel and increasing conventional safety culture are also new challenges. Regulatory requirements and practices need to be adapted to the continuously changing situation in order to maintain a flexible and proportionate balance between regulatory requirements and the changing nature of the residual risk.

The Release of Sites of Nuclear Installations (2006)
The process of decontamination and dismantling of nuclear installations generally results in disused materials (often in large quantities) and buildings that present no safety risk to the general public. Releasing such materials from regulatory control, e.g. for free use outside the nuclear industry, provides one option for their long term management. Other management possibilities include the recycling of these materials, especially metals, within the nuclear industry, and/or their direct emplacement in dedicated disposal facilities. Similarly, once a nuclear installation has been completely dismantled the final step involves the decontamination of the site for industrial (nuclear or non-nuclear) purposes, or for other uses (e.g. agricultural or recreational).

The step of removal of materials or a site from regulatory control is taken only after extensive surveys have shown that any resulting radiological exposure of the public will be trivial.

Decommissioning may be viewed as an opportunity to improve the sustainability of the host community, e.g. by helping to create added cultural or economic value that increase the quality of life over the years. Also, plant designs integrating reflection on the end use of the facility and site, or technical provisions for quick transitions to other types of facilities, provide better assurance to the host community that there will be flexibility for future planning.

Selecting Strategies for the Decommissioning of Nuclear Facilities (2006)
Many current plant operators intend to follow a strategy of ‘immediate dismantling’, following quickly upon a transition period following plant shut-down. Other operators prefer to defer dismantling for periods as long as several decades during which the residual radioactivity decays importantly while the facility or site is maintained in a safe condition.

The factors that affect the choice of decommissioning strategy are dependent on country- and facility-specific conditions. Site reuse considerations, the availability of a waste management path, the extent of knowledge of the plant’s history and the availability of equipment needed for the plant’s dismantling are the main factors considered. Relevant socio-economic considerations include future plans for regional development and local employment in the often remote site area. Inadequate pre-funding potentially creates a major constraint, which may make immediate dismantling impracticable in certain cases.